Highway guardrail post

ABSTRACT

A highway guardrail post comprises an elongated one-piece roll-formed metal body including a front wall defining an attachment face, a pair of opposing side walls orthogonal to the front wall, a first pair of inverted corners respectively connecting the pair of side walls to the front wall, and a second pair of inverted corners respectively extending from the pair of side walls and terminating in a pair of spaced rear edges to define a rear access opening opposite the front wall. The guardrail posts may be manufactured by roll-forming a metal sheet or coil and cutting the roll-formed metal sheet or coil into lengths.

FIELD OF THE INVENTION

The invention relates generally to guardrails (also referred to asfences or barriers) placed alongside roads and highways to stop errantvehicles, and more particularly to an improved support post for use inconstructing such guardrails.

BACKGROUND OF THE INVENTION

Safety barriers and guardrails are installed alongside highways androads as a means of stopping out-of-control vehicles. They may bestrategically located alongside curves and in zones where a steep drop,oncoming traffic, or other hazard awaits. A primary consideration inconstructing prior art barriers and guardrails is the ability towithstand vehicle impact, including impact from large trucks and buseswhich may be travelling at speed, to stop the vehicle.

Concrete safety barriers are quite strong, but do not yield to absorbvehicle kinetic energy. Consequently, they can be unsafe to passengersin a vehicle hitting the barrier, particularly if the vehicle is a smallvehicle or a heavy truck. Also, they are expensive to make andtransport.

Guardrails constructed by driving a plurality of vertical posts into theground at spaced intervals and connecting horizontal rails to thevertical posts are also known. The horizontal rails are typically aseries of W-beams bolted to the posts, or cables arranged to extendthrough U-bolts or eye-bolts connected to the posts. The rails arecommonly offset from the vertical posts by spacer blocks respectivelyfastened to the posts, wherein the W-beams or U-bolts or eye-bolts arefastened to the spacer blocks.

Vertical guardrail posts in widespread use include hot-formed steelI-beams, shown in FIG. 1, and solid wooden posts. These tend to be heavyand require significant force to drive into the ground, especially whererocks protrude into pre-dug post holes. Where steel I-beams are used,the I-beams will sometimes bend if they hit an obstruction such as arock while being driven into the ground. When this occurs, the bentI-beam may no longer be suitable for use, and may be quite difficult toremove from the ground because it is no longer straight.

Cold-formed steel posts are also known, particularly in Europe. Theseinclude C-channel, U-channel, and sigma channel cross-sections asdepicted in FIG. 2A, 2B, and 2C, respectively. These posts arecold-formed from steel sheet or coil of suitable thickness, e.g. 5 mm,and subsequently treated (e.g. galvanized) to improve weathering.

SUMMARY OF THE INVENTION

A highway guardrail post of the present invention generally comprises anelongated one-piece roll-formed metal body including a front walldefining an attachment face, a pair of opposing side walls orthogonal tothe front wall, a first pair of inverted corners respectively connectingthe pair of side walls to the front wall, and a second pair of invertedcorners respectively extending from the pair of side walls andterminating in a pair of spaced rear edges to define a rear accessopening opposite the front wall. The guardrail posts may be manufacturedby roll-forming a metal sheet or coil and cutting the roll-formed metalsheet or coil into lengths.

The invention also encompasses a guardrail assembly generally comprisinga plurality of guardrail posts as summarized above, and a horizontalrail connected to the front wall of each of the plurality of guardrailposts.

The invention further provides a method of making a plurality ofguardrail posts generally comprising the steps of (i) providing anelongated rectangular sheet or coil of metal having a longitudinalcentral axis and a pair of lateral edges parallel to and equidistantfrom the central axis; (ii) feeding the sheet or coil of metallengthwise into a roll-forming machine, wherein the roll-forming machineis configured to form a plurality of right-angle bend pairs, each bendpair being arranged symmetrically about the central axis, wherein theplurality of bend pairs includes, in order of progression from thecentral axis toward the pair of lateral edges, a first pair of internalbends, a first pair of external bends, a second pair of internal bends,a third pair of internal bends, and a second pair of external bends; and(iii) cutting the roll-formed sheet or coil of metal into lengths.

BRIEF DESCRIPTION OF THE DRAWING VIEWS

The invention will be explained further with reference to drawingfigures in which:

FIG. 1 is an orthogonal view showing a hot-rolled I-beam guardrail postof the prior art;

FIG. 2A, 2B, and 2C are cross-sectional views showing cold-formedguardrail posts of the prior art;

FIG. 3 is an orthogonal view of a cold-formed guardrail post of thepresent invention;

FIG. 4 is a top plan view of the guardrail post shown in FIG. 3;

FIG. 5 is a front elevational view of a guardrail assembly made usingcold-formed guardrail posts in accordance with the present invention;

FIG. 6 is an elevational view, partially sectioned, showing nestedW-beams fastened directly to the top portion of a guardrail post of thepresent invention;

FIG. 7 is a view similar to that of FIG. 6, however the W-beams areshown connected to the guardrail post by way of a spacer block;

FIG. 8 is an orthogonal view showing a plurality of cables connecteddirectly to a guardrail post of the present invention by U-bolts(eye-bolts may be substituted for the depicted U-bolts);

FIG. 9 is a view similar to that of FIG. 8, however the cables are shownconnected to the guardrail post by way of a spacer block;

FIG. 10 is a plan view showing various roll-forming bend locations on arectangular piece of sheet or coil stock from which guardrail posts inaccordance with FIGS. 3 and 4 may be cold formed by a roll-formingmachine; and

FIG. 11 is an end view of the rectangular piece of sheet or coil stock,schematically showing which side of the sheet or coil stock is contactedby forming rollers to form the various bends as the sheet or coil stockis passed through a roll-forming machine.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 3-4 show a roll-formed metal guardrail post 10 configured inaccordance with an embodiment of the present invention. Guardrail post10 comprises an elongated one-piece body that includes a front wall 12defining an attachment face 12A, a pair of opposing side walls 14 and 16orthogonal to the front wall 12, a first pair of inverted corners 18respectively connecting the pair of side walls to the front wall, and asecond pair of inverted corners 20 respectively extending from the pairof side walls and terminating in a pair of spaced rear edges 22 todefine a rear access opening 24 opposite front wall 12.

In the present specification, the term “inverted corner” refers to ajunction between two adjacent walls (e.g. front wall 12 and side wall14) wherein each wall includes a respective bend (e.g. bends 26 and 28)such that a corner bend where the walls meet (e.g. bend 30) pointstoward an interior region of guardrail post 10. In the embodiment shown,bends 26, 28 and 30 are right-angle bends, however other angles may beused, so long as the corner bend 30 points inward rather than outward.

As seen in FIG. 3, front wall 12 includes a through-hole 32 near a topend of post 10 for receiving a fastener used to attach a rail member orspacer block to the post as described in greater detail below. One ormore through-holes 32 may be provided depending on attachmentrequirements. Through-hole 32 may be elongated for easier alignment witha corresponding hole in a rail member or spacer block.

In one embodiment, a distance Dl between attachment face 12A and a planeP1 containing rear edges 22 may be equal to a distance D2 betweenrespective external faces 14A and 16A of side walls 14 and 16. In thisway, the overall dimension of guardrail post 10 front-to-rear may be thesame as its overall dimension side-to-side. In the same embodiment, orin an independent embodiment, the width W1 of each of the pair of sidewalls 14, 16 may be greater than the width W2 of front wall 12. In thesame embodiment, or in an independent embodiment, the rear accessopening 24 may have a width W3 equal to the width W2 of front wall 12.

FIGS. 5 and 6 illustrate a guardrail assembly 40 made using cold-formedguardrail posts 10 in accordance with the present invention. Guardrailassembly 40 generally comprises a plurality of vertical guardrail posts10 spaced from one another, and a horizontal rail 50 connected to thefront wall 12 of each of the guardrail posts 10. As best seen in FIG. 6,horizontal rail 50 may be constructed of overlapping, substantiallyrigid “W-beams” 52 known in the art of highway guardrails. One W-beam52, or two overlapping W-beams 52, may be fastened directly against theattachment face 12A of a post 10 by a threaded fastener 54 and a nut 56mated with fastener 54. Fastener 54 may be arranged to extend throughaligned holes in the W-beams and also through through-hole 32 to theinterior of guardrail post 10. A washer 57 may be provided between nut56 and an internal face of front wall 12. Where two W-beams overlap at aguardrail post 10, as shown in FIG. 6, additional fasteners 58 and nuts60 may be used to fasten the W-beams to one another. As depicted in FIG.5, the length of W-beams 52 and the spacing between guardrail posts 10may be chosen such that adjacent W-beams 52 overlap at every otherguardrail post 10.

As shown in FIG. 7, guardrail assembly 40 may further comprise a spacerblock 64 fastened directly against the attachment face 12A of eachguardrail post 10, wherein the horizontal rail 50 is connected to thefront wall 12 of the guardrail post by way of the spacer block. Spacerblock 64, itself known in the guardrail art, is typically made of wood,plastic, or steel. Spacer block 64 and W-beams 52 may be fastened to apost 10 by one elongated fastener 54 and mating nut 56, similar to thearrangement shown in FIG. 6. Alternatively, a pair of fasteners may beused, one through the W-beams 52 and into a front portion of spacerblock 64, and the other in an opposite direction through through-hole 32and into a rear portion of spacer block 64.

Reference is made now to FIGS. 8 and 9, which illustrate that horizontalrail 50 may be embodied as a flexible cable 70 or plurality of flexiblecables 70 connected to the front wall 12 of each guardrail post 10 by arespective U-bolt 72 through which the cable extends. Eye-bolts may besubstituted for U-bolts 72. As shown in FIG. 9, a spacer block 64 may beinstalled between cables 70 and guardrail post 10.

Methods of making guardrail posts 10, and constructing guardrailassemblies 40, will now be described.

Reference is made now to FIGS. 10 and 11. To make guardrail posts 10, anelongated rectangular sheet or coil of metal 80 is provided having alongitudinal central axis and a pair of lateral edges 22 parallel to andequidistant from the central axis. The sheet or coil of metal is fedlengthwise into a conventional roll-forming machine of a type having aseries of stations with rollers set up to progressively form bends inthe sheet or coil of metal. To manufacture the embodiment depicted inFIGS. 3 and 4, the roll-forming machine is configured to form aplurality of right-angle bend pairs, each bend pair being arrangedsymmetrically about the central axis. The plurality of bend pairsincludes, in order of progression from the central axis toward the pairof lateral edges, a first pair of internal bends 26, a first pair ofexternal bends 30, a second pair of internal bends 28, a third pair ofinternal bends 29, and a second pair of external bends 31. The locationof the bends is indicated schematically in

FIGS. 10 and 11. FIG. 11 also indicates which side of sheet or coil 80is contacted by rollers of the roll-forming machine to form the variousbends. In FIG. 11, internal bends are made by contacting what isinitially a top surface of sheet or coil 80, while external bends aremade by contacting what is initially a bottom surface of sheet or coil80. As will be understood, this roll-forming arrangement may beinverted.

The method of making guardrail posts 10 also comprises the step ofcutting the roll-formed sheet or coil of metal 80 into lengthscorresponding to the height of each guardrail post. By way of example,sheet or coil 80 may be an initial length of material that is cut into aplurality of 75-inch (1.91 meter) or 72-inch (1.83 meter) lengths afterroll-forming. If the roll-forming machine is equipped with a cut-offmechanism, then the lengths may be cut as the roll-formed sheet or coilis discharged from the roll-forming machine.

Holes 32 may be formed by a drilling, milling, or punching operationperformed at spaced intervals along sheet or coil 80 prior to, during,or after roll-forming. Each of the plurality of holes is located betweenthe first pair of internal bends 26, such as along the central axis.

With respect to moisture-proofing, it is advantageous that sheet or coil80 be pre-galvanized before roll-forming, thereby obviating the need forthe finished posts to be dipped after roll-forming. Sheet or coil 80 maybe cold-rolled steel, 3 mm thick, and may be hot dip galvanized. Ofcourse, other materials and treatments may be used.

Guardrail assembly 40 is constructed by driving guardrail posts 10vertically into the ground at spaced intervals, and then connectinghorizontal rail 50 to the posts as described above. Guardrail posts 10may be driven the same way guardrail posts of the prior art are driven,which typically involves the use of an automated post driver. Pilotholes may be provided in the ground to locate each post prior toengagement by the automated post driver. Guardrail posts 10 of thepresent invention have improved performance during installation overprior art guardrail posts because front wall 12 and side walls 14, 16will deflect inward when a large rock or other obstacle is encountered,but the overall post will remain straight, making it easier to pull thepost out of the ground than a prior art post, which will bend under thesame circumstances and become difficult to extract.

It will be appreciated that access opening 24 in each post 10 gives aninstaller easy access to the interior of the post so that the installermay tighten nut 56 onto threaded fastener 54, or drive a fastener toattach spacer block 64, as the case may be. In a current embodiment, theaccess opening is at least 2.75 inches (70 mm) wide.

1. A guardrail post comprising an elongated one-piece roll-formed metalbody including a front wall defining an attachment face, a pair ofopposing side walls orthogonal to the front wall, a first pair ofinverted corners respectively connecting the pair of side walls to thefront wall, and a second pair of inverted corners respectively extendingfrom the pair of side walls and terminating in a pair of spaced rearedges to define a rear access opening opposite the front wall.
 2. Theguardrail post according to claim 1, wherein the front wall includes athrough-hole for receiving a fastener.
 3. The guardrail post accordingto claim 1, wherein a distance between the attachment face and a planecontaining the pair of rear edges is equal to a distance betweenrespective external faces of the pair of side walls.
 4. The guardrailpost according to claim 3, wherein each of the pair of side walls iswider than the front wall.
 5. The guardrail post according to claim 4,wherein the rear access opening is equal in width to the front wall. 6.A guardrail assembly comprising: first and second vertical guardrailposts spaced from one another, each guardrail post comprising anelongated one-piece roll-formed metal body including a front walldefining an attachment face, a pair of opposing side walls orthogonal tothe front wall, a first pair of inverted corners respectively connectingthe pair of side walls to the front wall, and a second pair of invertedcorners respectively extending from the pair of side walls to define arear access opening opposite the front wall; and a horizontal railconnected to the front wall of each of the first and second guardrailposts.
 7. The guardrail assembly according to claim 6, wherein thehorizontal rail is a substantially rigid section fastened directlyagainst the attachment face of at least one of the vertical guardrailposts.
 8. The guardrail assembly according to claim 6, wherein thehorizontal rail is a flexible cable connected to the front wall of eachof the first and second guardrail posts by a respective U-bolt oreye-bolt.
 9. The guardrail assembly according to claim 6, furthercomprising a spacer block fastened directly against the attachment faceof at least one of the first and second guardrail posts, wherein thehorizontal rail is connected to the front wall of the at least oneguardrail post by way of the spacer block.
 10. The guardrail assemblyaccording to claim 9, wherein the horizontal rail is a substantiallyrigid section fastened directly against a surface of the spacer block.11. The guardrail assembly according to claim 9, wherein the horizontalrail includes a flexible cable connected to the spacer block by a U-boltor an eye-bolt.
 12. A method of making a plurality of guardrail postscomprising the steps of: providing an elongated rectangular sheet orcoil of metal having a longitudinal central axis and a pair of lateraledges parallel to and equidistant from the central axis; feeding thesheet or coil of metal lengthwise into a roll-forming machine, whereinthe roll-forming machine is configured to form a plurality ofright-angle bend pairs, each bend pair being arranged symmetricallyabout the central axis, wherein the plurality of bend pairs includes, inorder of progression from the central axis toward the pair of lateraledges, a first pair of internal bends, a first pair of external bends, asecond pair of internal bends, a third pair of internal bends, and asecond pair of external bends; and cutting the roll-formed sheet or coilof metal into lengths.
 13. The method according to claim 12, furthercomprising the step of forming a plurality of holes through the sheet orcoil of metal at spaced locations along the length of the sheet or coil,wherein each of the plurality of holes is between the first pair ofinternal bends.
 14. The method according to claim 12, wherein the sheetor coil of metal is hot rolled steel coil.
 15. The method according toclaim 14, wherein the hot rolled steel coil is provided as galvanizedhot rolled steel coil.